Supramolecular dynamic binary complexes with pH and salt-responsive properties for use in unconventional reservoirs

Area of Science:

• Materials Science
• Chemical Engineering
• Petroleum Engineering

Background:

• Hydraulic fracturing is crucial for unconventional reservoir energy production.
• Developing sustainable and efficient fracturing fluids is an ongoing research priority.
• Current fluids face challenges in performance and environmental impact.

Purpose of the Study:

• To introduce a novel dynamic binary complex (DBC) solution for hydraulic fracturing.
• To evaluate the properties and potential applications of this new fluid system.
• To explore its responsiveness to environmental stimuli like pH and salinity.

Main Methods:

• Formation of a supramolecular structure via self-assembly of oleic acid and diethylenetriamine.
• Characterization of the fluid's rheological properties, including viscosity under shear.
• Testing of sand-settling capabilities and responsiveness to pH and salinity variations.

Main Results:

• A viscous gel was formed with <2 wt% constituents in an aqueous solution.
• The DBC solution exhibited high viscosity, even under shear.
• Tunable zero-shear viscosity (factor of ~280) by pH change and enhanced viscosity in saline conditions.
• Effective sand particle suspension demonstrated.

Conclusions:

• The dynamic binary complex (DBC) solution shows significant potential as a hydraulic fracturing fluid.
• Its smart, salt-responsive, and pH-switchable characteristics offer advantages for reservoir stimulation.
• This environmentally conscious fluid design addresses the need for improved fracturing fluid technology.